Pulp-molded lid and molding device thereof

ABSTRACT

The present invention relates to a pulp-molded lid and its molding device. The molding device comprises a first lid molding die and a second lid molding die. The first lid molding die comprises a snap-fit molding part and a rim molding part, so that a snap-fit section of the pulp-molded lid and a circular rim section at the edge of the pulp-molded lid are formed when the first lid molding die and the second lid molding die are coupled with each other. The rim section and the snap-fit section are used to strengthen the combination of the pulp-molded lid and an external container, so that the combination is more stable.

INCORPORATION BY REFERENCE

The present application is based on, and claims priority from, Taiwanese application number 105130752, filed on Sep. 23, 2016 to TIPO, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to a pulp-molded lid, particularly a pulp-molded lid and a molding device thereof wherein the pulp-molded lid comprises a snap-fit section which is formed with the pulp-molded lid integrally and coupled with a cup.

2. Description of the Prior Art

Paper cups and bowls are disposable consumables ubiquitous in our daily lives. Currently, the manufacturers considering costs of manufacturing materials and requests for distinct products have created various methods to manufacture these disposable consumables.

To manufacture a paper product with firm texture or styling or a thicker layer, a manufacturer should deposit paper pulp to a certain thickness for molding. However, if paper products are extruded from a thicker layer of deposited paper pulp in a conventional manufacturing process which aims at manufacturing thinner paper cups or bowls, it is quite often to see the appearance of convex edges or irregular surface wrinkles of the paper products. These disfigures the aesthetic exteriors or structural strength of those paper products.

Furthermore, an appropriate manufacturing process based on pulp molding (also known as the pulp die molding method) developed recently is applicable to paper products with a certain thickness. However, the inside embossed or barb-like patterns which contribute to securing the combination of a cup lid and a paper cup are mostly disposed on the rim and/or the snap-fit section of an ordinary pulp-molded cup lid and shaped on a formed lid in a secondary local roll-extrusion process.

In this regard, there is an increased time cost in a secondary roll-extrusion process for rework which also often causes defects or disfigurements to the lids which are the finished products.

SUMMARY OF THE INVENTION

To solve the problems in the prior arts, an integrated pulp-molded lid provided in the present disclosure reduces manufacturing time and costs.

The pulp-molded lid comprises a central section and a rim section which encircles the central section, accommodates an upper wall edge of an external container coupled with the pulp-molded lid, and clamps the wall edge of the external container.

Furthermore, the rim section comprises a snap-fit section, which is downwardly connected with the upper wall edge of the external container, manufactured with the central section as well as the rim section integrally, and further coupled with a protrusion encircling the external container for a firm combination of the pulp-molded lid and the external container when the rim section clamps the upper wall edge of the external container.

To manufacture the pulp-molded lid, the present disclosure provides a molding device of a pulp-molded lid which comprises a first lid molding die and a second lid molding die: the first lid molding die comprises a first molding unit with a center molding part for shaping of the corresponding central section of the pulp-molded lid and a rim molding part for shaping of the corresponding rim section of the pulp-molded lid; the rim molding part comprises a snap-fit molding part recessed from an outer edge of the rim molding part and situated at one side far away from the center molding part for shaping of the snap-fit section of the pulp-molded lid; the second lid molding die comprises a second molding unit for shaping of a corresponding exterior profile of the pulp-molded lid.

As mentioned previously, a manufacturing process of a pulp-molded lid in the present disclosure is similar to that of a conventional pulp-molded lid in general. In pulp-based hot press molding steps, the elastic pulp-molded lid features the snap-fit section which is slightly deformed for separation from the snap-fit molding part in a de-molding process and characteristic of a profile similar to that of the snap-fit molding part. As such, the snap-fit section is coupled with a protrusion extended outward from a cup rim of an external container which is to be connected to the snap-fit section at the pulp-molded lid as required in standards of product manufacturing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a pulp-molded lid;

FIG. 2 is a sectional view which illustrates both a pulp-molded lid and an external container joined together;

FIG. 3 is a schematic view which illustrates a second lid molding die in a molding device of a pulp-molded lid;

FIG. 4 is a schematic view which illustrates a first lid molding die in a molding device of a pulp-molded lid;

FIG. 5 is a sectional view which illustrates a molding device of a pulp-molded lid in disengaged status;

FIG. 6 is a sectional view of a lid pulp-sucking and molding device for a pulp-molded lid;

FIG. 7A is the first schematic view which illustrates a molding device of a pulp-molded lid in a de-molding process;

FIG. 7B is the second schematic view which illustrates a molding device of a pulp-molded lid in a de-molding process;

FIG. 7C is the third schematic view which illustrates a molding device of a pulp-molded lid in a de-molding process; and

FIG. 8 is a flow diagram for steps in a manufacturing process of using a molding device of a pulp-molded lid.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The features, content, advantages and effects of a pulp-mold lid and a molding device thereof in the present disclosure are explained in embodiments and accompanying drawings which are schematic views to illustrate the patent specification but not intended to limit the scope of patent claims.

Referring to FIG. 1 which is a sectional view of a pulp-molded lid 1 comprising a central section 10 and a rim section 12 encircling the central section 10 and having two side walls and a top edge part for development of an inverted U-shaped profile and further an annular snap-fit section 14 at an inner surface of the rim section 12 being disposed away from a side wall of the central section 10 and protruding inward.

Referring to FIG. 2, which illustrates the pulp-molded lid 1 easily connected and coupled with an external container 3 by means of the rim section 12 clamps the entire upper edge of an exterior wall of the external container 3 preferably. As shown in FIG. 2, the snap-fit section 14 abuts and contacts a protrusion 300 outwardly raised or rolled from the upper edge of an exterior wall of the external container 3, contributing to a better combination of the pulp-molded lid 1 and the external container 3. It can be seen that either the rim section 12 or the snap-fit section 14 is designed to secure the pulp-molded lid 1 and the external container 3 as required in standards of product manufacturing.

A pulp-molded lid of an ordinary paper cup in which a beverage would normally be carried, the pulp-molded lid 1 in FIG. 1 comprises the circular central section 10 with a convex part raised from the edge and a concave part at the center of the central section 10 in an embodiment; the central section 10 comprises an opening from which beverages inside are drawn and a perforation drilled or pressed into the concave part to balance pressure in a container filled with beverages. However, it should be reiterated that the opening or the perforation is not a primary technical feature for a pulp-molded lid herein.

Referring to FIGS. 3 to 5, which illustrate a molding device of a pulp-molded lid comprises a first lid molding die 22 and a second lid molding die 20. The first lid molding die 22 comprises a first molding unit 220 with a center molding part 2201 and a rim molding part 2202 wherein the center molding part 2201 and the rim molding part 2202 are used in shaping an interior profile of the central section 10 of the pulp-molded lid 1 and an interior profile of the rim section 12 of the pulp-molded lid 1, respectively. Moreover, the first lid molding die 22 comprises a snap-fit molding part 2203 which is designed on the rim molding part 2202 for shaping of the rim section 12 and at one side far away from the central section 10 and used to form the snap-fit section 14 of the pulp-molded lid 1; the second lid molding die 20 comprises a second molding unit 200 designed at one side and used in shaping an exterior profile of the pulp-molded lid 1.

Referring to FIG. 6, which illustrates a strainer 226 is installed on the first molding unit 220 of the first lid molding die 22 and a plurality of pore channels 2204 are uniformly distributed on the first lid molding die 22 for development of a first lid pulp-sucking and molding die used in a practical process. In an embodiment of a pulp-molded lid, each of the pore channels 2204 is opened on an outer edge of the rim molding part 2202 of the first molding unit 220, between the center molding part 2201 and the rim molding part 2202, and the topmost end of the center molding part 2201. As such, the strainer 226 lowered into a pulp tank makes paper pulp subside in a first lid pulp-sucking and molding die 22A as no pulp fibers migrate across the strainer 26 and each of the pore channels 2204 from which external air is drawn provides suction to absorb pulp fibers, draining excessive water without jams of the pore channels 2204 and shaping a raw pulp-molded lid 1 inside the first lid pulp-sucking and molding die 22A. Furthermore, a plurality of pore channels 2021 are opened on the second molding unit 200 of the second lid molding die 20 for development of a second lid pulp-sucking and molding die 20A. In the embodiment, each of the pore channels 2021 is further opened on an outer edge of the second molding unit 200 and opposite to the center molding part 2201 as well as the rim molding part 2202 of the first molding unit 220. As such, the second lid pulp-sucking and molding die 20A and the first lid pulp-sucking and molding die 22A are coupled with each other for supply of suction induced by outward exhaled air to the pore channels 2021 through which a raw pulp-molded lid is sucked by the second lid pulp-sucking and molding die 20A from the first lid pulp-sucking and molding die 22A.

Furthermore, when the first lid molding die 22 is bored for placement of a heating rod and a thermocouple or the first lid molding die 22 casted with thermal conductive materials is securely installed on a heating plate in the embodiment, a first lid heating and molding die, which is heated directly or via thermal conduction to increase temperature of the first molding unit 220 inside and dry paper pulp, is created; on the other hand, when the second lid molding die 20 is bored for placement of a heating rod and a thermocouple or the second lid molding die 20 casted with thermal conductive materials is securely installed on another heating plate, a second lid heating and molding die, which is heated directly or via thermal conduction to increase temperature of the second molding unit 200 inside and dry paper pulp, is created and comprises a plurality of pore channels 2021 through which the dried pulp-molded lid 1 is drawn. It should be reiterated that neither the first molding unit 220 in the first lid molding die 22 nor the second molding unit 200 in the second lid molding die 20 are provided with a strainer 226 inside.

Referring to FIGS. 7A, 7B and 7C, which are schematic views illustrating a molding device of a pulp-molded lid in a de-molding process. A pulp-molded lid is drawn by the corresponding second lid pulp-sucking and molding die 20A and removed from the first lid pulp-sucking and molding die 22A in a continuous process, as shown in schematic partial enlargement views which present a relationship between the snap-fit molding part 2203 at the edge of the first lid molding die 22 or the first lid pulp-sucking and molding die 22A and the pulp-molded lid 1.

Referring to FIG. 7A in which there is no second lid pulp-sucking and molding die displayed. FIG. 7A illustrates status before a de-molding process that the raw pulp-molded lid 1 shaped in a pulp molding process is securely attached to and matches the profile of the snap-fit molding part 2203 at the edge of the first lid molding die 22 through the strainer 226 and the snap-fit section 14 of the pulp-molded lid 1 fits into the strainer 226.

Referring to FIG. 7B, which illustrates the raw pulp-molded lid 1 shaped in a pulp molding process is drawn by the second lid pulp-sucking and molding die 20A and gradually separated from the first lid molding die 22 in the first lid pulp-sucking and molding die 22A as well as the attached strainer 226. As shown in FIG. 7B, the snap-fit section 14 of the pulp-molded lid 1, which is made of flexible paper and extended a bit, is being removed from but still squeezed by the snap-fit molding part 2203 and slightly deformed in a de-molding process of separating a die from the other upward.

Referring to FIG. 7C, which illustrates the raw pulp-molded lid 1 shaped in a pulp molding process is drawn by the second lid pulp-sucking and molding die 20A and totally separated from the first lid molding die 22 as well as the attached strainer 226. As shown in FIG. 7C, because of the flexibility of paper, the snap-fit section 14 of the pulp-molded lid 1, which was separated from the first lid pulp-sucking and molding die 22A and deformed partially, is slightly reconstituted and overall matches the profile of the snap-fit molding part 2203 as appropriate but possibly leaves some distinct squeezed and deformed or truncated parts which have no adverse effect on a pulp-molded lid with a manufacturing process corrected for better fastening strength between the snap-fit section 14 and a convex part of an external container 3.

Referring to FIG. 8, which illustrates a flow diagram for a manufacturing process of using a molding device of a pulp-molded lid to shape a pulp-molded lid according to steps as follows:

Step S801: the first molding unit is covered with pulp slurry when the first lid pulp-sucking and molding die is immersed in pulp slurry.

Step S802: the first lid pulp-sucking and molding die is removed from pulp slurry and excessive water, which is included in pulp slurry deposited on the first molding unit and unused in a manufacturing process, is drained from the pore channels and the strainer.

Step S803: the second lid pulp-sucking and molding die is driven to fit into the first lid pulp-sucking and molding die so that a raw lid featuring a profile similar to that of a desired pulp-molded lid is shaped with dehydrated paper pulp adhered to and matching the strainer on the first molding unit.

Step S804: the raw lid is sucked by the second lid pulp-sucking and molding die through the pore channels for separation from the first lid pulp-sucking and molding die in a de-molding process.

Step S805: the raw lid is held in the first lid heating and molding die with which the second lid pulp-sucking and molding die is coupled.

Step S806: the second lid heating and molding die is driven to fit into the first lid heating and molding die completely for sealing the raw lid between the first and second lid heating and molding dies.

Step S807: the raw lid is heated and dried by the first lid heating and molding die as well as the second lid heating and molding die and totally dehydrated for shaping of the pulp-molded lid.

Step S808: the pulp-molded lid is sucked by the second lid heating and molding die for separation.

According to a manufacturing process from step S801 to step S808, a pulp-molded lid is shaped.

An alternative manufacturing process different from that of the above embodiment is introduced in the present disclosure. In the alternative embodiment, the profile of a first molding unit (a second molding unit) in a lid pulp-sucking and molding die (as well as a lid heating and molding die) is exchanged to the profile of a second molding unit (a first molding unit). When a molding unit to shape an exterior profile of a pulp-molded lid is first immersed in pulp slurry and driven to fit into another molding unit which is used to shape an interior profile of a snap-fit section on the pulp-molded lid, a pulp-molded lid featuring an identical profile can be created with two dies at reversed positions.

In summary, a pulp-molded lid and a molding device thereof for once-and-for-all die molding of a snap-fit section in the patent application, which are innovative work in technical ideas and features several effects in contrast to conventional molded lids, meets novelty and non-obviousness for patentability. 

What is claimed is:
 1. A pulp-molded lid, which is made of paper pulp and comprises a central section at the center and an annular rim section encircling the central section and having two side walls and further a snap-fit section extended from the outside one of the two side walls, protruding inward; wherein the snap-fit section is integrally formed with the pulp-molded lid; and wherein when an external container is coupled to the pulp-molded lid, the snap-fit section expands and then contracts based on physical elasticity of paper pulp so that the pulp-molded lid can couple to a protrusion extended from a cup rim of the external container.
 2. A molding device of a pulp-molded lid for manufacturing of the pulp-molded lid as claimed in claim 1, comprising: a first lid molding die, which comprises a first molding unit for shaping of a complete interior profile of the pulp-molded lid wherein the first molding unit has a center molding part for shaping of the central section of the pulp-molded lid and a rim molding part for shaping of the rim section of the pulp-molded lid and the rim molding part has an annular snap-fit molding part situated at an outer edge and at one side far away from the center molding part for shaping of the snap-fit section of the pulp-molded lid; and a second lid molding die, which comprises a second molding unit for shaping of a complete exterior profile of the pulp-molded lid and is driven to fit into the first lid molding die for shaping of the pulp-molded lid between the second lid molding die and the first lid molding die.
 3. A molding device of a pulp-molded lid as claimed in claim 2 wherein the first molding unit optionally comprises a plurality of pore channels penetrating the first molding unit inside and each of the pore channels creates suction by which excessive water in pulp slurry during shaping of the pulp-molded lid is drained or pressure in a pulp molding process is regulated.
 4. A molding device of a pulp-molded lid as claimed in claim 2 wherein the second molding unit optionally comprises a plurality of pore channels penetrating the second molding unit inside and each of the pore channels is used to regulate pressure during shaping of the pulp-molded lid or create suction by which the pulp-molded lid is sucked and separated from the first lid molding die.
 5. A molding device of a pulp-molded lid as claimed in claim 3 wherein the second molding unit optionally comprises a plurality of pore channels penetrating the second molding unit inside and each of the pore channels is used to regulate pressure during shaping of the pulp-molded lid or create suction by which the pulp-molded lid is sucked and separated from the first lid molding die.
 6. A molding device of a pulp-molded lid as claimed in claim 2 wherein the first lid molding die is provided with a strainer adhered to the first molding unit and immersed in paper pulp for construction of a first lid pulp-sucking and molding die and the strainer comprises a plurality of fine meshes to filter paper pulp and keep pulp fibers attached and paper pulp deposited on the first lid pulp-sucking and molding die, covered over the first molding unit, and correspondingly applied to the second lid molding die for shaping of the pulp-molded lid by the second molding unit in a second lid pulp-sucking and molding die.
 7. A molding device of a pulp-molded lid as claimed in claim 3 wherein the first lid molding die is provided with a strainer adhered to the first molding unit and immersed in paper pulp for construction of a first lid pulp-sucking and molding die and the strainer comprises a plurality of fine meshes to filter paper pulp and keep pulp fibers attached and paper pulp deposited on the first lid pulp-sucking and molding die, covered over the first molding unit, and correspondingly applied to the second lid molding die for shaping of the pulp-molded lid by the second molding unit in a second lid pulp-sucking and molding die.
 8. A molding device of a pulp-molded lid as claimed in claim 2 wherein the second lid molding die which is casted with thermal conductive materials for heating and drying paper pulp and shaping the pulp-molded lid is a second lid heating and molding die; and the first lid molding die which is casted with thermal conductive materials for heating and drying paper pulp and shaping the pulp-molded lid is a first lid heating and molding die.
 9. A molding device of a pulp-molded lid as claimed in claim 3 wherein the second lid molding die which is casted with thermal conductive materials for heating and drying paper pulp and shaping the pulp-molded lid is a second lid heating and molding die; and the first lid molding die which is casted with thermal conductive materials for heating and drying paper pulp and shaping the pulp-molded lid is a first lid heating and molding die.
 10. A molding device of a pulp-molded lid for manufacturing of the pulp-molded lid as claimed in claim 1, comprising: a first lid molding die, which comprises a first molding unit for shaping of a complete exterior profile of the pulp-molded lid; a second lid molding die, which comprises a second molding unit for shaping of a complete interior profile of the pulp-molded lid wherein the second molding unit has a center molding part for shaping of the central section of the pulp-molded lid and a rim molding part for shaping of the rim section of the pulp-molded lid and the rim molding part has an annular snap-fit molding part situated at an outer edge and at one side far away from the center molding part for shaping of the snap-fit section of the pulp-molded lid; wherein the second lid molding die and the first lid molding die are coupled with each other for shaping of the pulp-molded lid with paper pulp held between the second lid molding die and the first lid molding die.
 11. A molding device of a pulp-molded lid as claimed in claim 10 wherein the first molding unit optionally comprises a plurality of pore channels penetrating the first molding unit inside and each of the pore channels creates suction by which excessive water in pulp slurry during shaping of the pulp-molded lid is drained or pressure in a pulp molding process is regulated.
 12. A molding device of a pulp-molded lid as claimed in claim 10 wherein the second molding unit optionally comprises a plurality of pore channels penetrating the second molding unit inside and each of the pore channels is used to regulate pressure during shaping of the pulp-molded lid or create suction by which the pulp-molded lid is sucked and separated from the first lid molding die.
 13. A molding device of a pulp-molded lid as claimed in claim 11 wherein the second molding unit optionally comprises a plurality of pore channels penetrating the second molding unit inside and each of the pore channels is used to regulate pressure during shaping of the pulp-molded lid or create suction by which the pulp-molded lid is sucked and separated from the first lid molding die.
 14. A molding device of a pulp-molded lid as claimed in claim 10 wherein the first lid molding die is provided with a strainer adhered to the first molding unit and immersed in paper pulp for construction of a first lid pulp-sucking and molding die and the strainer comprises a plurality of fine meshes to filter paper pulp and keep pulp fibers attached and paper pulp deposited on the first lid pulp-sucking and molding die, covered over the first molding unit, and correspondingly applied to the second lid molding die for shaping the pulp-molded lid by the second molding unit in a second lid pulp-sucking and molding die.
 15. A molding device of a pulp-molded lid as claimed in claim 11 wherein the first lid molding die is provided with a strainer adhered to the first molding unit and immersed in paper pulp for construction of a first lid pulp-sucking and molding die and the strainer comprises a plurality of fine meshes to filter paper pulp and keep pulp fibers attached and paper pulp deposited on the first lid pulp-sucking and molding die, covered over the first molding unit, and correspondingly applied to the second lid molding die for shaping the pulp-molded lid by the second molding unit in a second lid pulp-sucking and molding die.
 16. A molding device of a pulp-molded lid as claimed in claim 10 wherein the second lid molding die which is casted with thermal conductive materials for heating and drying paper pulp and shaping the pulp-molded lid is a second lid heating and molding die; and the first lid molding die which is casted with thermal conductive materials for heating and drying paper pulp and shaping the pulp-molded lid is a first lid heating and molding die.
 17. A molding device of a pulp-molded lid as claimed in claim 11 wherein the second lid molding die which is casted with thermal conductive materials for heating and drying paper pulp and shaping the pulp-molded lid is a second lid heating and molding die; and the first lid molding die which is casted with thermal conductive materials for heating and drying paper pulp and shaping the pulp-molded lid is a first lid heating and molding die. 